Field of the Invention
The present invention relates to compressed gas guns. More particularly, the present invention relates to compressed gas guns that employ a cocking mechanism, which yields a mechanical advantage for the compression of a main spring.
Description of the Related Art
Compressed gas guns operate to release a quantity of compressed gas into the breech of a barrel, which has been pre-loaded with a projectile, thereby propelling the projectile out of the barrel at high velocity. In practice, such a gun must provide a source of compressed gas in order to function. Typically, this source of gas is an air tank that is pre-charged prior to being coupled with the gun, or a fixed tank that is charged in place while coupled to the gun. As such, these are referred to as pneumatic pre-charged (PCP) guns. In either case, the tank holds a finite quantity of compressed gas. Upon discharging the gun one or more times, the reserve of compressed gas is ultimately depleted and must be replenished. Air is used as the compressed gas in the majority of PCP guns, but other suitable gases can be employed as well.
In the case of a manually loaded compressed gas gun, the breech of the barrel must be accessible for manual insertion of a projectile into the breech of the barrel. It is desirable to provide a readily accessible breech, which can be conveniently loaded by the fingers of the user. In the case of an auto-loading gun, the breech still must be accessible to the loading mechanism, yet sealable so as to coupled the compressed gas to the breech without undue gas leakage.
A valve mechanism is commonly provided which acts to discharge a quantity of compressed gas as a result of actuation of a trigger mechanism. However, prior to discharging the gun, the valve assembly must be coupled to the breech of the barrel in order to seal the gas port between the tank and the breech of the barrel. It is desirable to provide a pressure-tight seal, which serves to conserve the amount of gas consumed upon discharging the gun and also to conserve the pressure of the gas so as to maximize the amount of energy transferred from the compressed gas to the projectile. Furthermore, a tight gas seal reduces the sound level of the gun upon discharging, which is desirable in compressed gas guns.
The inventor of the present disclosure has been granted two prior patents, which are U.S. Pat. No. 5,586,545 issued on Dec. 24, 1996 for COMPRESSED GAS GUN, and U.S. Pat. No. 5,813,392 issued on Sep. 29, 1998 for COMPRESSED GAS GUN, which together disclose several embodiments of compressed gas guns. The entire disclosures of these two patents are hereby incorporated by reference. A review of those patents will reveal that the loading, cocking, and discharging mechanisms, collectively referred to as the operating assembly, incorporate a hammer and a mainspring where the compressed energy of the mainspring drives the hammer rearward in the receiver, and this energy is ultimately driven against a pneumatic valve to release a surge of compressed gas into the breech of a barrel to discharge the gun. It will also be noted that these designs were intended for lighter caliber projectiles, generally ranging from 0.17 inch to 0.25 inch calibers. The force of the main spring, weight of the hammer, and pneumatic valve actuation force are all related to the caliber and mass of the projectile. Since the forces required for lighter calibers are reasonable with respect to the force an operator must exert to compress the main spring, these prior design utilized a cocking lever that was directly coupled to the mechanism such that actuation of the cocking lever opened the breech seal, moved the hammer forward, and compressed the main spring in preparation of a subsequent discharge of the gun.
A growing trend in compressed gas guns is toward heavier caliber projectiles. Today, 0.30 inch caliber guns are known, and recently 0.45 inch caliber guns are entering the market. While the prior loading, cocking, and discharging mechanisms have performed well with lighter caliber guns, the higher forces required to discharge heavier calibers has correspondingly increased mainspring compressive forces, and the size and weight of related components, such that the operator applied cocking forces have become challenging for some operators. Thus it can be appreciated that there is a need in the art for a compressed gas gun that functions with heavier calibers, yet is manageable to operate.